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NVD / CVE Program· CNA GitHub_M

CVE-2026-34933: Avahi: Reachable assertion in `transport_flags_from_domain()` via conflicting publish flags crashes avahi-daemon

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.20% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: avahi avahi 0.9-rc4; azl3 avahi 0.8-7 on Azure Linux 3.0 0.8-8; azl3 avahi 0.8-8 on Azure Linux 3.0 0.8-8.

Low priority for now. Upgrade to avahi avahi 0.9-rc4; azl3 avahi 0.8-7 on Azure Linux 3.0 0.8-8; azl3 avahi 0.8-8 on Azure Linux 3.0 0.8-8 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. Prior to version 0.9-rc4, any unprivileged local user can crash avahi-daemon by sending a single D-Bus method call with conflicting publish flags. This issue has been patched in version 0.9-rc4.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 3, 2026
Updated
Jul 24, 2026
EPSS
0.2% · 10th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
5.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-34933

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
avahiavahi

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • avahi avahibefore 0.9
  • avahi avahi0.9

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • avahi avahi

    • < 0.9-rc4affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.24avahibefore 0.8-r260.8-r26
Debian:12avahifrom 0—
openSUSE:Leap 16.0avahibefore 0.8-160000.5.10.8-160000.5.1
openSUSE:Leap 16.0avahi-glib2before 0.8-160000.5.10.8-160000.5.1
openSUSE:Leap 16.0avahi-qt6before 0.8-160000.5.10.8-160000.5.1
openSUSE:Tumbleweedavahibefore 0.8-43.10.8-43.1
Red Hat:hummingbird:1avahibefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-autoipdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-howlbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-howl-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-libdns_sdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-compat-libdns_sd-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-dnsconfdbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-glibbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-glib-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-gobjectbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-gobject-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-libsbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt3before 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt3-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt4before 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt4-develbefore 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1
Red Hat:hummingbird:1avahi-qt5before 0:0.9~rc4-0.1.hum10:0.9~rc4-0.1.hum1

+12

Same product

avahi: all records

Other highest-scoring records for the same primary product.

  • CVE-2008-5081The originates_from_local_legacy_unicast_socket function (avahi-core/server.c) in avahi-daemon in Avahi before 0.6.24 allows remote attacker
    40Plan
  • CVE-2017-6519avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses that are not on-link, whic
    37Monitor
  • CVE-2021-26720avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via /etc/network/if-up.d/avahi-daemon, and allows a
    31Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2025-68468Jan 12, 2026 · Avahi has a reachable assertion in lookup_multicast_callback
    26Monitor
  • ← EarlierCVE-2025-68471Jan 12, 2026 · Avahi has a reachable assertion in lookup_start
    26Monitor
  • ← EarlierCVE-2026-24401Jan 24, 2026 · Avahi has Uncontrolled Recursion in lookup_handle_cname function
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
avahi avahi0.9-rc4 · descriptionVendor (CNA)
azl3 avahi 0.8-7 on Azure Linux 3.00.8-8 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 avahi 0.8-8 on Azure Linux 3.00.8-8 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 avahi 0.8-5 on CBL Mariner 2.00.8-6 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 avahi 0.8-5 on CBL-Mariner 2.00.8-6 · Release NotesMicrosoft (MSRC)
alpine:avahi0.8-r26 · Alpine:v3.24Package registry (OSV)
opensuse:avahi0.8-43.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:avahi-glib20.8-160000.5.1 · openSUSE:Leap 16.0Package registry (OSV)
opensuse:avahi-qt60.8-160000.5.1 · openSUSE:Leap 16.0Package registry (OSV)
red hat:avahi0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-autoipd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-howl0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-howl-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-libdns_sd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-compat-libdns_sd-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-dnsconfd0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-glib0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-glib-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-gobject0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:avahi-gobject-devel0:0.9~rc4-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
suse:avahi0.8-160000.5.1 · SUSE:Linux Micro 6.2Package registry (OSV)
suse:avahi-glib20.8-160000.5.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-6846881 days apartAvahi has a reachable assertion in lookup_multicast_callback
    26Monitor
  • CVE-2025-6847181 days apartAvahi has a reachable assertion in lookup_start
    26Monitor
  • CVE-2025-6827681 days apartAvahi has a reachable assertion in avahi_wide_area_scan_cache
    22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-617 · Reachable Assertion

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records